"The challenges in building something big are very different from just a lab bench demo," says Biercuk.

"There are all these mathematical tricks that people put in the theory to make everything work out perfectly but none of that is physical reality. Our work incorporates the physical reality."

Real-world conditions

Biercuk and colleagues now say they have a theoretical plan to build quantum memory suitable for large-scale "noisy" real-world conditions.

"Our approach is much more realistic," he says.

"It's theory that is very strongly supported by a whole variety of experiments that my group and others have done over the past five years or so."

Biercuk says the new approach satisfies the three competing needs of high-fidelity, long-time memory and quick on-demand retrieval. They say their calculations show it's possible for quantum states to last hours, long beyond the fractions of a second they last today.

"We've figured out from an engineering perspective how to put it all together to make these effective memories," he says.

Importantly, Biercuk and colleagues have tweaked a conventional error-suppression strategy, called "dynamic decoupling".

"If you do this error suppression in a very particular way, you can preserve the quantum states for very long times with very low error rates," says Biercuk.

"The beautiful thing is it can actually work for any technology," says Biercuk.

He says one of the next steps is to build experiments based on the blueprint.

"If we can do that then we have a very clear path to building a quantum memory," says Biercuk.

'Robust' protocol

Quantum computing expert Professor Gerard Milburn, from the University of Queensland, describes the protocol developed by Biercuk and colleagues as "robust".

"The importance of this paper is it shows a protocol, that's not technology specific, to enable one to build a good quantum memory even in the presence of significant noise and significant error," says Milburn.

"It relaxes some of the engineering requirements that we need to satisfy in building systems out of real stuff. You can make quantum memory in an easy environment and still get it to function."

Milburn says in the long run every quantum computer will need a quantum memory, which provides the simplest form of quantum computation.

But he says quantum computers are still a long way off and the most immediate impact of the latest findings will be on the building of quantum repeaters for use in quantum communication, including cryptography.